Power Supply Coil Whine
This article demonstrates one type of electrical buzzing noise (coil whine) that computer power supplies can generate under load. In this case, the unwanted noise comes from a Corsair HX100i Platinum PSU – a supposed premium product and chosen for a silent PC build because of its Zero RPM fan mode and its promised quiet and efficient operation.
Power Supply Units (PSUs) should not sound like this. This one was sent back for an exchange and the replacement was good.
During general desktop use, the power supply was silent. When required to fulfill demanding power requirements though, the PSU started to make a buzzing sound like sparks jumping the gap of a Van de Graaff generator and in some instances, like chirping crickets.
It was difficult to determine the power supply as the source of these noises when it was in situ within the PC case. Noise from cooling fans and spinning hard disk drives can make the noisy culprit difficult to determine by putting your ear inside the computer case. The only way I could make a determination was to remove the power supply from the case and place a demanding load on the PSU. This made it much easier to identify the noise source.
I used the Furmark GPU stress test to make the power demand.
This video demonstrates the electrical buzzing noise from the Corsair HX1000i power supply when put under load and how the noise stops when that demand is removed.
As per Corsair’s recommendations for curing noisy PSUs, all power saving options were disabled on the motherboard and in Windows prior to recording.
- 02 seconds : mouse click to start the Furmark GPU stress test. Straight away, the unwanted PSU buzzing noise can be heard.
- 12 seconds : this is the noise from the GPU fan. However, the electrical noise from the Corsair PSU can still be heard.
- 24 seconds : mouse click to end the Furmark GPU stress test. The PSU noise and the GPU fan both stop.
- 29 seconds : the Furmark GPU stress test is repeated and the Corsair power supply noise can heard after the mouse click.
- 48 seconds : Corsair power supply details shown during the Furmark GPU stress test. Power draw 187W in and 172W out.
- 59 seconds: Furmark GPU stress test ends and PSU noise stops.